1. Technical Field
The present invention relates to a method of calculating a moving state of a moving object and the like.
2. Related Art
Techniques of estimating moving states including quantities such as a position, a velocity, and a moving direction of a moving object moving in a movement space using a state estimating technique in a state space have been invented. The Kalman filter is widely known as the state estimating technique. For example, JP-A-2010-266468 discloses a technique of estimating a position of a moving object using the Kalman filter.
In the estimation of a moving state using the Kalman filter, a moving state of a moving object changing from time to time is sequentially estimated using observation information including an error. Reference information detected, for example, by an external sensor (a sensor such as a global positioning system (GPS) sensor, an inertial sensor, or a geometric sensor, which is hereinafter comprehensively referred to as a “reference sensor”) is used as the observation information.
However, the above-mentioned techniques have a problem in that estimation accuracy of a moving state depends on only detection accuracy of the reference sensor. That is, when the detection accuracy of the reference sensor is low, inaccurate reference information is used as the observation information for calculation of the Kalman filter and thus there is a problem in that accuracy of the estimated moving state is lowered due to inclination to the observation information.